The present invention relates to footwear, and more particularly, to a method for manufacturing footwear.
Most conventional footwear includes an upper, within which a wearer's foot is positioned, and a sole, which generally forms a ground contacting, wear layer positioned beneath the wearer's foot. The upper and sole are usually separately manufactured, then joined with one another to complete the footwear.
Each footwear model typically is constructed in a wide variety of standard shoe sizes to ensure that the model can be offered to and fit a significant cross section of potential footwear consumers. There are a variety of different sizing systems to characterize “standard” shoe size measurements, for example, the U.S. system, the English system, the Parisian system, the Mondopoint system and the Asian system. Usually, these systems have shoe sizes that are divided into full and partial sizes, for example, under the U.S. system, the standard sizes usually are provided in full sizes, such as 8, 9, 10, etc., as well as half sizes, such as 8½, 9½, 10½, etc., to closely approximate and fit well a wearer's foot.
To make such a wide variety of sizes for a particular footwear model, manufacturers typically have to produce multiple different uppers and multiple different outsoles for each full shoe size and for each corresponding half shoe size. For example, for a single footwear model, a first upper pattern is created for a U.S. size 9½ shoe, and a second upper pattern is created for a U.S. size 9 shoe (along with all other desired sizes). Likewise, a first sole mold is created to mold a sole of proportionate size and shape to the U.S. size 9½ first upper pattern, and a second sole mold is created to mold another, different sole of proportionate size and shape to the U.S. size 9 second upper pattern. Accordingly, two separate lasts typically are used to construct the two different upper patterns, and two separate molds are used to mold the two different outsoles to create the two different sized shoes corresponding to the same footwear model.
The extra set of molds and lasts, and related retooling and operation, for the different soles and uppers can create a significant cost and labor burden on manufacturers. Basically, for each footwear model that has full U.S. shoe sizes 2 through 13 and corresponding half sizes, 2½ through 13½, the manufacturer might invest in, make and dedicate 24 different lasts for uppers and 24 different molds for corresponding soles. Again, this can result in a significant investment just to produce a given footwear model.
Another issue with most footwear is that the upper is constructed from multiple individual pieces of material. Those pieces are cut from stock material and usually modified in thickness for the particular footwear. Then they are joined with one another typically by stitching or cementing to form a three-dimensional upper. The pieces of the upper also are shaped over a last to better define the shape of the upper. After the pieces of the upper are assembled, a liner typically is then joined with them, again with more stitching or gluing. If the footwear is to include laces, eyelets must be formed on the upper.
All of the foregoing steps require substantial labor input. Moreover, the amount of labor required is compounded by the fact that every time a new footwear model and its various shoe sizes are desired, the manufacturing method must be retooled to accommodate the variations. Unfortunately, while many have tried to address the labor intensity issues concerning footwear, they remain as much a problem now as they did at the turn of the century.
Accordingly, there remains much room for improvement to provide a footwear manufacturing method and related footwear that is flexible enough to accommodate multiple models and sizes of footwear, and that generally reduces the amount of labor and time input for manufacturing the footwear.